Free standing or whip antennas generally comprise of an upstanding tapered length presenting a base at the bottom end thereof and a free end at the upper end. Such base antennas are used to receive and transmit signals and may be located on land or a ship.
Various attempts have heretofore been made in the prior art in order to strengthen the whip antennas that can be subjected to severe weather conditions in terms of wind or snow blowing.
For example U.S. Pat. No. 3,725,944 illustrates an antenna constructed exclusively of fibreglass with the sole exception of the electrical conductors, couplings, and upper and lower ends, which may incorporate fibreglass or some other materials.
Also U.S. Pat. No. 4,500,888 teaches a free standing antenna formed with an elongated tubular body portion having one or more sections and an enlarged base portion at its lower end for mounting thereof, and the body portion having a plurality of layers of reinforcing filaments some of the layers being bundles of longitudinal filament rovings running lengthwise, and other of the layers being generally circumferential windings of filament rovings, the layers being bonded together by resin material; electrically conducted materials embedded in the tubular structure and running from end to end, an annual electrically conductive collar connected to the conductive elements adjacent the lower end of the structure, a female threaded socket connected to the collar, and extending through a wall of the tubular structure for connection from the exterior, at least one layer of the woven reinforcing filament cloth material extending up the interior of the tubular structure adjacent the lower end, and overlying the interior of the collar, and, resin bonding the layer of woven cloth material to the interior of the tubular structure, and to the interior of the collar.
Furthermore U.S. Pat. No. 5,357,261 illustrates a whip antenna having a base member being formed of glass fibres reinforced resin materials.
Other arrangements of free standing antennas are shown in U.S. Pat. No. 4,914,450 which shows a flat ribbon-like conductor which is wound around a fibre glass rod.
U.S. Pat. No. 4,214,247 relates to a turnable fibreglass whip antenna comprising an elongated fibreglass core having a conductive wire coiled a round the core and serving as the antenna. The upper most extremity of the wire is tightly coiled around an axial bore within the fibreglass. A metal insert, fixed within the fibreglass bore is in threaded engagement with a setscrew accessible from the top of the antenna.
Furthermore, U.S. Pat. No. 4,161,737 shows a stepped, tapered helical antenna having tightly wound loading coils between each of the different helical sections, and the loading coils are wound in a stepped, tapered mathematical progression.
Furthermore, some prior art whip antennas need to be operated in pairs aboard a ship or on land in order to extend the operation frequency range required in operation as shown in Canadian Patent No. 2,114,661.
It is an object of this invention to provide an improved free standing antenna which is easier to manufacture than shown in the prior art.
It is a further object of this invention to provide an antenna to be operated substantially instantaneously within a selected frequency band.
It is an aspect of this invention to provide a freestanding antenna extending longitudinally to present a base and a free end, comprising a helical conductor disposed over an insulated metallic tube.
It is another aspect of this invention to provide a whip antenna comprising inductive coils having a plurality of selected number of turns disposed over an insulated aluminium tube.
Yet another aspect of this invention relates to a method of producing a whip antenna comprising: tapering a length of aluminium tube, applying a high velocity plasma coating, having a nickel based alloy powder, applying a winding a ribbon conductor with a plurality with a selected number of turns along said tube, and applying a layer of polymer coating.
These and other objects and features of the invention shall now be described in relation to the follow drawings: